Aminomethyl derivatives of benzothiazolinethione as lubricant additives

ABSTRACT

The invention relates to lubricant compositions comprising 
     (a) one or more mineral oils or synthetic oils and 
     (b) 0.05 to 5% by weight of at least one compound of formulae I, II and III ##STR1## wherein R 1 , R 2 , R 3 , R 4  and R 5  are as defined in claim 1; and 
     (c) further optional lubricant additives. 
     Some of these compounds are new and can be prepared by Mannich reaction from the appropriate 2-mercaptobenzothiazoles, an aldehyde R 2  --CHO and a primary or secondary mono- or diamine. These Mannich bases are useful additives for lubricants for reducing friction, wear, corrosion and oxidation.

This is a division of application Ser. No. 866,189 filed on May 22, 1986now U.S. Pat. No. 4,737,302 issued on Apr. 12, 1988.

The present invention relates to lubricant compositions containingoil-soluble derivatives of benzothiazoline-2-thione as lubricantadditives and to the compounds themselves where novel.

It is customary to treat mineral and synthetic lubricants with additivesto improve their performance properties. Particularly useful additivesare those that protect the machine which it is desired to lubricate fromwear. It is required of these additives that they shall increase theload-carrying capacity of the lubricant, that they shall not have acorrosive action on the metal parts to be protected, and that they shallhave good heat resistance.

For this utility it is preferred to use phosphorus and sulfur-containingcompounds such as salts of dialkyldithiophosphates (q.v. CRC Handbook ofLubrication, Vol. 2 (1984), 301-315, CRC Press Inc.). In view of the useof catalysts in exhaust gas systems of combustion engines, however, thephosphorus content of lubricating oils shall be kept to a minimum toprevent the catalysts from becoming deactivated [H. S. Gandhi et al.,Applied Catalysis 3, (1982), 79-82].

It has now been found that that specific oil-soluble derivatives ofbenzothiazole that are free from phosphorus exhibit excellent propertiesin mineral and synthetic lubricants with respect to wear, load-carryingcapacity, protection of metal parts from corrosion and ash content. Inlubricant formulations containing reduced amounts of zincdialkyldithiophosphates, these derivatives afford substantially betterprotection against oxidation. Specifically, these compounds areN-aminomethyl derivatives of benzothiazoline-2-thione.

Accordingly, the present invention relates to lubricant compositionswhich comprise

(a) one or more mineral oils or synthetic oils and

(b) 0.05 to 5% by weight of at least one compound of formula I, II orIII ##STR2## wherein

R¹ is hydrogen, C₁ -C₁₂ alkyl, C₂ -C₄ alkoxy, C₂ -C₂₄ alkoxycarbonyl ornitro,

R² is hydrogen, C₁ -C₁₂ alkyl, 2-furyl, phenyl or phenyl which issubstituted by C₁ -C₄ alkyl, C₁ -C₄ alkoxy, C₂ -C₂₄ alkoxycarbonyl ornitro,

R³ and R⁴ are each independently of the other hydrogen, C₁ -C₂₀ alkylwhich may be interrupted by one or more members selected from O, S and Nor which may contain oxo or thiono groups; or are C₃ -C₂₄ alkenyl, C₃-C₁₂ alkoxyalkyl, C₅ -C₈ cycloalkyl, phenyl or phenyl which issubstituted by C₁ -C₁₂ alkyl, C₁ -C₄ alkoxy, C₂ -C₂₄ alkoxycarbonyl ornitro; or are naphthyl, C₇ -C₉ phenylalkyl, 2-furylmethyl or2-(tetrahydrofuryl)methyl; or R³ and R⁴, together with the nitrogen atomto which they are attached, form a 5- or 6-membered ring which, inaddition to containing the N-atom, may also contain further hetero atomsselected from O, N and S or oxo or thiono groups, or may be fused to abenzene nucleus; and

R⁵ is C₂ -C₁₂ alkylene which may be interrupted by O, N or S or maycontain oxo or thiono groups; or is C₆ -C₁₅ cycloalkylene, C₆ -C₁₅arylene, carbonyl or thiocarbonyl or, in formula III, is the --N(R³)--R⁵--N(R³)-- group a piperazin-1,4-diyl radical which may be substituted byone or more methyl groups, as additives, which reduce friction, wear,corrosion and oxidation in (a); and (c) further optional lubricantadditives.

R¹, R², R³ and R⁴ are alkyl may be unbranched or branched and are e.g.methyl, ethyl, isopropyl, n-butyl, sec-butyl, tert-butyl, isoamyl,n-hexyl, 2-ethylbutyl, 1-methylpentyl, 1,3-dimethylbutyl, 2-ethylhexyl,isoheptyl, n-octyl, 1-methylheptyl, 1,1,3-trimethylhexyl, n-decyl,1-methylundecyl or n-dodecyl. R³ and R⁴ as alkyl may also be tetradecyl,hexadecyl, octadecyl or eicosyl.

R¹ and R² as alkoxy may be methoxy, ethoxy, isopropoxy or n-butoxy.

R¹ as alkoxycarbonyl contains 2 to 24 carbon atoms in the alkyl moietyand may be methoxycarbonyl, ethoxycarbonyl or 2-ethylhexoxycarbonyl.

R², R³ and R⁴ may be alkoxycarbonyl-unsubstituted phenyl, wherealkoxycarbonyl is as defined for R¹.

R², R³ and R⁴ may be substituted phenyl such as tolyl, xylyl,4-tert-butylphenyl, 3-methoxyphenyl, 4-propoxyphenyl,3-butoxycarbonylphenyl, 3-nitrophenyl or 4-methyl-3-nitrophenyl.

R³ and R⁴ as alkoxyalkyl may be 2-methoxyethyl, 2-isopropoxyethyl,2-butoxyethyl or 2-octyloxyethyl. R³ and R⁴ as cycloalkyl may becyclopentyl, cyclohexyl, 4-methylcyclohexyl or cyclooctyl. R³ and R⁴ asphenylalkyl may be benzyl, 2-phenylethyl, 1-phenylethyl or2-phenylpropyl. If R³ and R⁴, together with the N-atom to which they areattached, for a 5- or 6-membered ring, said ring may be a pyrrolidone,piperidine, morpholine, thiomorpholine, piperazine, indole,tetrahydroquinoline or tetrahydroisoquinoline ring. R³ and R⁴ as alkenylmay be allyl, methallyl, 1-pentenyl, dodecenyl or octadecenyl.

R⁵ as alkylene may be unbranched or branched alkylene or may also beinterrupted by O, S or N, and is e.g. di-, tri-, tetra-, hexa-, octa-,deca- or dodecamethylene; 2,2,4- or 2,4,4-trimethylhexamethylene,3-oxapentamethylene, 4-thiaheptamethylene or4-(methylaza)heptamethylene.

R⁵ as cycloalkylene may be 1,4-cyclohexylene, 1,4-decahydronaphthylene,cyclohexane-1,4-dimethylene or dicyclohexylmethane-4,4-diyl. R⁵ asarylene may be 1,3-phenylene, 1,4-phenylene, 1,4-naphthylene,4,4'-diphenylene, diphenylmethane-4,4'-diyl or diphenyl oxide-4,4'-diyl.

The sum of the carbon atoms contained in the radicals R¹, R², R³, R⁴ andR⁵ is preferably more than 10, most preferably more than 14. Theseradicals contribute to the solubility in oil.

Lubricant compositions are preferred which comprise 0.1 to 3% by weightof at least one compound of formula I, II or III.

Lubricant compositions are preferred which contain compounds of formulaI, II or III, wherein R² is hydrogen and, in particular, wherein R¹ alsois hydrogen.

Lubricant compositions are preferred which contain compounds of formulaI, II or III, wherein R¹ and R² are hydrogen, R³ and R⁴ are eachindependently of the other hydrogen, C₁ -C₂₄ alkyl, C₃ -C₂₄ alkenyl,cyclohexyl, phenyl, phenyl which is substituted by C₁ -C₁₂ alkyl or C₁-C₂₄ alkoxycarbonyl, or are C₇ -C₁₀ phenylalkyl, 2-methoxyethyl or3-methoxypropyl, and R⁵ is C₂ -C₁₂ alkylene.

Lubricant compositions are most preferred which contain a compound offormula ##STR3##

Examples of eligible compounds of formula I are:

3-[bis(2-ethylhexyl)aminomethyl]benzothiazole-2-thione

3-(dicyclohexylaminomethyl)benzothiazoline-2-thione

3-(diphenylaminomethyl)benzothiazoline-2-thione

3-[bis(4-dodecylphenyl)aminomethyl]benzothiazoline-2-thione

3-[dibenzylaminomethyl]benzothiazoline-2-thione

3-[N-(1-naphthylo)phenylaminomethyl]benzothiazoline-2-thione

3-[N-(2-furylmethyl)butylaminomethyl]benzothiazoline-2-thione

3-[N-(2-tetrahydrofurylmethyl)hexylaminomethyl]benzothiazoline-2-thione

3-[bis(2-methoxyethyl)aminomethyl]benzothiazoline-2-thione

3-(piperidinomethyl)benzothiazoline-2-thione

3-(pyrrolidinomethyl)benzothiazoline-2-thione

3-(moropholinomethyl)benzothiazoline-2-thione

3-[(2,3-dihydroindolyl)methyl]benzothiazoline-2-thione

3-[(1,2,3,4-tetrahydroquinolyl)methyl]benzothiazoline-2-thione

3-(phenylaminomethyl)benzothiazoline-2-thione

3-[(4-dodecylphenyl)aminomethyl]benzothiazoline-2-thione

3-[bis(2-ethylhexyl)aminomethyl]5-carbethoxybenzothiazoline-2-thione.

Examples of compounds of formula II are:

N,N-bis(2-thionobenzothiazolin-3-ylmethyl)-2-ethylhexylamine

N,N-bis(2-thionobenzothiazolin-3-ylmethyl)-n-dodecylamine

N,N-bis(2-thionobenzothiazolin-3-ylmethyl)-3-ethoxypropylamine.

Examples of compounds of formula III are:

N,N'-bis(2-thionobenzothiazolin-3-ylmethyl)-N,N'-dimethylethylenediamine

N,N'-bis(2-thionobenzothiazolin-3ylmethyl)piperazine

N,N'-bis(2-thionobenzothiazolin-3-ylmethyl)-2,5-dimethylpiperazine

N,N'-bis(2-thionobenzothiazolin-3-ylmethyl)-4,4'-diaminodicyclohexylmethane

N,N'-bis(2-thionobenzothiazolin-3-ylmethyl)-p-phenylenediamine.

The lubricants for which the additives of this invention are suitablemay be lubricating oils or greases based on mineral oils or on syntheticoils or mixtures thereof. Examples of synthetic oils are ester oils,olefin polymers or ethylene oxide polymers.

The additives can also be dissolved beforehand in a small quantity ofoil and the concentrate so obtained is then added to the lubricant.

In addition to containing the additives of formula I, II or III, thelubricant may also contain other additives customarily employed forlubricants. Examples of such additives are antioxidants, metalpassivators, corrosion inhibitors, viscosity improvers, pour-pointdepressants, dispersants, surfactants, or other antiwear additives. Forlubricating greases, thickeners are added to the oils.

Examples of antioxidants are:

(a) Alkylated and non-alkylated aromatic amines and mixtures thereof,for example: dioctyldiphenylamine, mono-tert-octylphenyl-α- and-β-naphthylamines, phenotriazine, dioctylphenothiazine,phenyl-α-naphthylamine, N,N'-di-sec-butyl-p-phenylenediamine.

(b) Sterically hindered phenols, for example:2,6-di-tert-butyl-p-cresol, 4,4'-bis(2,6-diisopropylphenol),2,4,6-triisopropylphenol, 2,2'-thiobis(4-methyl-6-tert-butylphenol),4,4'methylene-bis(2,6-di-tert-butylphenol).

(c) Esters of thiodipropionic acid or thiodiacetic acid, for example:dilaurylthiodipropionate or dioctylthiodiacetate.

(d) Salts of carbamic and dithiophosphoric acids, for example: antimonydiamyldithiocarbamate, zinc diamyldithiophosphate.

Examples of metal deactivators are:

(a) for copper, e.g.: benzotriazole, tetrahydrobenzotriazole,2-mercaptobenzotriazole, 2,5-dimercaptothiadiazole, salicyclidenepropylenediamine, salts of salicylaminoguanidine.

(b) for lead, e.g.: sabacic acid derivatives, quinizarine, propylgallate.

Examples of rust inhibitors are:

(a) Organic acids, the esters, metal salts and anhydrides thereof, e.g.:N-oleyl sarcosine, sorbitan monooleate, lead naphthenate,dodecenylsuccinic anhydride.

(b) Nitrogen-containing compounds for example: Primary, secondary ortertiary aliphatic or cycloaliphatic amines and amine salts of organicand inorganic acids, for example oil-suluble alkylammonium carboxylates.Heterocyclic compounds, e.g. substituted imidazolines and oxazolines.

(c) Sulfur-containing compounds, for example: bariumdinonylnaphthalenesulfonates, calcium petroleum sulfonates.

Examples of viscosity index improvers are:

polymethacrylates, vinyl pyrrolidone/methacrylate copolymers,polybutene, olefin copolymers, styrene/acrylate copolymers.

Examples of pour-point depressants are:

alkylated naphthalenes, alkylated phenols, polymethacrylates.

Examples of surfactants and dispersants are:

polyalkenylsuccinimides, oil-soluble metal soaps such as calcium,barium, magnesium and aluminium carboxylates, phenolates or sulfonates.

Examples of other antiwear additives are:

Compounds containing sulfur and/or phosphorus and/or halogen, e.g.sulfurised vegetable oils, zinc dialkyl dithiophosphates,tritolylphosphate, chlorinated paraffins, alkyl and aryl disulfides.

Some of the compounds of formula I, II or III are known and some arenovel compounds. Known compounds of formula I are those wherein R¹ andR² are hydrogen and R³ and R⁴ together contain not more than 14 carbonatoms. Such compounds are obtained by a Mannich reaction of2-mercaptobenzothiazole with formaldehyde and a primary or secondaryamine.

Halasa and Smith, J. Org. Chem. 36 (1971), 636-641, have shown that,under the customary conditions of Mannich reactions, theaminomethylation of 2-mercaptobenzothiazole takes place at the N-atom ofthe tautomeric form of benzothiazoline-2-thione.

Among the compounds of formulae I, II and III, those compounds are novelin which R¹ or R² is not hydrogen. Among the compounds of formula I,those compounds are novel wherein (a) R¹ and R² are hydrogen and R³ andR⁴ together contain more than 14 carbon atoms, as well as those in which(b) R¹ and R² are hydrogen, R³ and R⁴ are aliphatic or cycloaliphaticradicals and together contain more than 10 carbon atoms. Among thecompounds of formula II, those compounds are novel in which the radicalsR² and R³ together contain more than 10 carbon atoms. Among thecompounds of formula III, those compounds are novel in which R⁵ is notan arylene radical.

The invention therefore also relates to compounds of formula I ##STR4##wherein R¹ is C₁ -C₁₂ alkyl, C₁ -C₄ alkoxy, C₂ -C₂₄ alkoxycarbonyl ornitro and R², R³ and R⁴ are as previously defined.

Preferred compounds of formula I are those wherein R² is hydrogen.

Particularly preferred compounds of formula I are those wherein R¹ andR² are hydrogen, R³ and R⁴ are as previously defined and togethercontain more than 14 carbon atoms.

The most preferred compounds of formula I are those wherein R¹ and R²are hydrogen, R³ and R⁴ are each independently of the other hydrogen, C₁-C₂₄ alkyl, C₃ -C₂₄ alkenyl, C₃ -C₁₂ alkoxyalkyl or C₅ -C₈ cycloalkyl,and R³ and R⁴ together contain more than 10 carbon atoms and,preferably, wherein R³ and R⁴ each independently of the other are C₆-C₁₂ alkyl or cyclohexyl or both are 2-ethylhexyl.

The invention further relates to compounds of formula II ##STR5##wherein R¹ is C₁ -C₁₂ alkyl, C₁ -C₄ alkoxy, C₂ -C₂₄ alkoxycarbonyl ornitro, and R² and R³ are as previously defined.

Preferred compounds of formula II are those wherein R² is hydrogen.Particularly preferred compounds of formula II are those wherein R¹ andR² are hydrogen and R³ contains more than 10 carbon atoms.

The invention also relates to compounds of formula III ##STR6## whereinR¹ is C₁ -C₁₂ alkyl, C₁ -C₄ alkoxy, C₂ -C₂₄ alkoxycarbonyl or nitro, andR², R³ and R⁵ are as previously defined.

Preferred compounds of formula III are those wherein R² is hydrogen.Particularly preferred compounds of formula III are those wherein R¹ andR² are hydrogen and R³ and R⁵ are as previously defined, with theproviso that R⁵ is not arylene; and, most particularly, compounds offormula III in which R³ is hydrogen, C₁ -C₂₄ alkyl or C₃ -C₂₄ alkenyl,and R⁵ is C₂ -C₁₂ alkylene.

The compounds of formula I are obtained by reaction of a2-mercaptobenzothiazole of formula IV with a monoamine R³ --NH--R⁴ andan aldehyde R² --CHO: ##STR7## The amine can be a primary or secondarymonoamine and the reaction is carried out in approximately equimolarratio with a small excess of aldehyde. The preferred reaction medium isa non-polar solvent, preferably toluene, cyclohexane or ligroin.However, it is also possible to use a polar solvent, in particular analcohol such as ethanol or methanol. As described by Halasa and Smith,it is also possible first to form the appropriate water-soluble aminesalt of formula IV and then to react this salt, in aqueous medium, withthe aldehyde.

The compounds of formula II are prepared by reaction of IV with R² --OHand a primary monoamine R³ --NH₂ in the molar ratio 2:2:1:

    2IV+2R.sup.2 --CHO+R.sup.3 --NH.sub.2 →             II

The compounds of formula III are prepared by Mannich reaction using adiamine R³ --NH--R⁵ --NH--R³ :

    2IV+2R.sup.2 --CHO+R.sup.3 --NH--R.sup.5 --NH--R.sup.3 →III

The diamine may be a primary or secondary diamine. It is preferred touse a primary diamine (R³ ═H).

The following Examples serve to illustrate the invention.

EXAMPLE 1

Mannich reaction in methanol/water

To a suspension of 250.8 g (1.5 moles) of 2-mercaptobenzothiazole in1500 ml of methanol are added 112.8 ml (1.5 moles) of 37% aqueousformaldehyde, followed by the dropwise addition, with stirring, of 362.4g (1.5 moles) of bis(2-ethylhexyl)amine. The mixture is stirred for 15hours at 50° C. and then concentrated by evaporation in vacuo, affordingas residue 618 g of3-[bis(2-ethylhexyl)aminomethyl]benzothiazoline-2-thione as a reddishbrown oil

Analysis calculated: C 68.52%; H 9.58%; N 6.66%; S 15.24% found: 68.36%;9.57%; 6.69%; 15.29%.

EXAMPLE 2

Mannich reaction in ethanol/water

With stirring, 18.63 g (0.2 mole) of aniline are added to a suspensionof 33.45 g (0.2 mole) of 2-mercaptobenzothiazole in 120 ml of ethanol,the temperature rising to 30° C. Then 16.4 g (0.2 mole) of 37% aqueousformaldehyde solution are added and stirring is continued for 30minutes. The precipitate is isolated by filtration and washed with coldethanol and hexane, affording 47 g of3-(phenylaminomethyl)benzothiazoline-2-thione which melts at 102°-103°C.

Analysis calculated: C 61.74%; H 4.44%; N 10.29%; S 23.54%. found:61.53%; 4.43%; 10.10%; 23.79%.

In similar manner,3-(dodecylphenylaminomethyl)-benzothiaszoline-2-thione is obtained as abrown oil starting from technical dodecylaniline (mixture of isomers).

EXAMPLE 3

Mannich reaction in toluene/water

10.12 g (13.7 ml; 0.01 mole) of dipropylamine and 8.3 g (7.6 ml; 0.1mole) of 36% aqueous formaldehyde are added dropwise to a suspension of16.7 g (0.1 mole) of 2-mercaptobenzothiazole in 40 ml of toluene. Themixture is stirred vigorously for 5 hours at 50° C. The small aqueousphase is separated and the toluene phase is concentrated by evaporationin vacuo, affording as residue 26.4 g of yellowish orange crystals of3-(dipropylaminomethyl)benzothiazoline-2-thione which melts at 60°-62°C.

Analysis calculated: C 59.96%; H 7.19%; N 9.99%; S 22.86%. found:59.82%; 7.20%; 9.89%; 22.86%.

The Examples listed in the subsequent Tables 1-3 are carried out incorresponding manner. In these Tables

method A=procedure according to Example 1

method B=procedure according to Example 2

method C=procedure according to Example 3.

In the column "Analysis", the data in the first line always indicate thetheoretical values and the data in the second line the values found (inpercentages).

                                      TABLE 1                                     __________________________________________________________________________     ##STR8##                                                                      Example                                                                            ##STR9##          methodPreparatory                                                                    Yield (g)                                                                          Aspect   m.p. (°C.)                                                                   CH NSAnalysis              __________________________________________________________________________                                                      (%)                               ##STR10##        A/C    98/97                                                                              dark yellow viscous oil                                                                --    68.52 68.36                                                                        9.58 9.57                                                                        6.66 6.69                                                                       15.24 15.29       2                                                                                   ##STR11##        B      89   beige-coloured crystalline                                                             102-103                                                                             61.74 61.53                                                                        4.44 4.43                                                                       10.29 10.10                                                                      23.54 23.79       3    N(CH.sub.2 CH.sub.2 CH.sub.3).sub.2                                                             C      94   yellowish orange                                                                       60-62 59.96                                                                              7.19                                                                             9.99                                                                            22.86                                                crystalline solid                                                                            59.82                                                                              7.20                                                                             9.89                                                                            22.86             4    mixture:                                                                      NHC.sub.14 H.sub.27                                                                             C      95   brown oil                                                                              --    66.62                                                                              9.05                                                                             7.40                                                                            16.93                  NHC.sub.12 H.sub.25                          66.51                                                                              9.25                                                                             7.62                                                                            16.96             5                                                                                   ##STR12##        B      92   dark brown viscous oil                                                                 --    70.86 71.22                                                                        8.23 8.33                                                                        6.36 6.14                                                                       14.55 14.19            mixture of isomers                                                       6    N(CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3).sub.2                                                    C      92   brown oil                                                                              --    62.29                                                                              7.84                                                                             9.08                                                                            20.78                                                               62.32                                                                              7.83                                                                             8.91                                                                            20.87             7                                                                                   ##STR13##        C      91   beige-coloured crystalline                                                             102-106                                                                             62.29 62.89                                                                        7.84 7.66                                                                        9.08 9.07                                                                       20.78 21.05       8    N(C.sub.13 H.sub.27).sub.2                                                                      C      97   brownish yellow                                                                        --    72.8.                                                                             10.78                                                                             4.99                                                                            11.43                                                oil            72.60                                                                             10.73                                                                             4.88                                                                            11.41             9    N(C.sub.18 H.sub.37).sub.2                                                                      C      99   yellow crystalline                                                                     65    75.36                                                                             11.50                                                                             3.99                                                                             9.14                                                solid          75.56                                                                             11.54                                                                             3.98                                                                             9.16             10                                                                                  ##STR14##        B      95   brown viscous oil                                                                      --    63.97 63.93                                                                        5.37 5.42                                                                        9.32 9.13                                                                       21.34 21.10       11                                                                                  ##STR15##        B      92   yellow crystalline solid                                                               85-87 64.93 64.52                                                                        5.77 5.75                                                                        8.76 8.76                                                                       29.39 21.08       12                                                                                  ##STR16##        B      90   yellow crystalline solid                                                               96-98 70.18 70.05                                                                        5.35 5.43                                                                        7.44 7.37                                                                       17.03 17.22       13                                                                                  ##STR17##        B      97   yellow crystalline solid                                                               152-156                                                                             59.05 59.04                                                                        6.10 6.10                                                                       10.60 10.27                                                                      24.25 24.26       14                                                                                  ##STR18##        B      79   yellow crystalline solid                                                               134-137                                                                             54.11 54.12                                                                        5.30 5.25                                                                       10.52 10.01                                                                      24.07 24.77       15   N(CH.sub.2 CH.sub.2OCH.sub.3).sub.2                                                             B      96   brownish yellow                                                                        --    53.82                                                                              6.45                                                                             8.97                                                                            20.52                                                oil            53.93                                                                              6.51                                                                             8.75                                                                            19.91             __________________________________________________________________________

                                      TABLE 2                                     __________________________________________________________________________                                   Preparatory         Analysis (%)               Example                                                                            Compound                  method Yield (g)                                                                          Aspect  C  H  N  S                 __________________________________________________________________________    16                                                                                  ##STR19##                C      95   brown oil                                                                             65.81 65.95                                                                      9.00 9.22                                                                        5.68 5.59                                                                        13.01 12.90       17                                                                                  ##STR20##                C      95   orange-red oil                                                                        61.90 62.12                                                                      8.44 8.56                                                                        9.02 8.97                                                                        13.77             __________________________________________________________________________                                                                13.55         

                                      TABLE 3                                     __________________________________________________________________________     ##STR21##                                                                                          Preparatory                                                                          Yield                 Analysis (%)               Example                                                                            NR               method  (g)                                                                              Aspect      m.p. (°C.)                                                                   C  H  N  S                 __________________________________________________________________________    18                                                                                  ##STR22##       C      97  brown viscous oil                                                                         --    59.1. 59.09                                                                      5.99 6.08                                                                        8.62 8.27                                                                        26.29 25.81       19   NC.sub.18 H.sub.37                                                                             C      88  yellow crystalline solid                                                                  90-92 65.02                                                                            7.86                                                                             6.69                                                                             20.42                                                                65.19                                                                            7.94                                                                             6.52                                                                             20.31             20   NC.sub.18 H.sub.35                                                                             C      99  pale yellow wax                                                                           --    -- -- -- --                                                                   -- -- 6.68                                                                             20.35             21                                                                                  ##STR23##       C      93  yellow crystalline solid                                                                  158-163                                                                             59.32 61.14                                                                      4.11 4.54                                                                        9.02 8.34                                                                        27.54             __________________________________________________________________________                                                                25.80         

EXAMPLE 22

Antiwear test

The antiwear test is carried out by ASTM Standard Method D 2783-81 usingthe Shell four-ball machine. Th base oil employed in the test isCatenex® P 941 (ex Shell). The values obtained are (a) the weld load(WL), i.e. the load (in kg) at which welding of the 4 balls occurs over10 seconds, and (b) the wear scar diameter (WSD) at a load of 40 kg over1 hour (in mm).

1% weight of additive is used in all test samples. The results arereported in Table 4.

                  TABLE 4                                                         ______________________________________                                        Additive from                                                                 Example         WL (kg)  WSD (mm)                                             ______________________________________                                        1               180      0.55                                                 3               200      0.60                                                 5               180      0.55                                                 6               180      0.55                                                 7               180      0.60                                                 8               200      0.55                                                 9               180      0.60                                                 10              180      0.60                                                 12              180      0.60                                                 15              180      0.65                                                 16              180      0.55                                                 17              200      0.50                                                 19              180      0.60                                                 20              200      0.60                                                 --              160      0.90                                                 ______________________________________                                    

EXAMPLE 23

Test for copper deactivation

A brightly polished copper plate measuring 60×10×1 mm is immersed inturbine oil which contains 50 ppm of dissolved sulfur as well as 0.5% of3-[bis(2-ethylhexyl)aminomethyl]benzothiazoline-2-thione. A comparisonsample contains no thiazoline derivative. The samples are heated to 100°C. for 2 hours. The copper plates are then washed with petroleum ether,dried, and the colour is determined in accordance with ASTM D 130 bycomparison with a standard colour chart. Evaluation is made by a ratingof 1-4:

1--untarnished

2--moderate tarnish

3--pronounced tarnish

4--corrosion

Result:

colour of sample 1 B

comparison sample 3 B

EXAMPLE 24

Oxidation stabilising test

(TFOUT Test: Thin-film Oxygen Uptake Test)

This test is a modified version of the Rotary Bomb Oxidation Test forMineral Oils (ASTM D 2272). A full description will be found in C. S. Kuand S. M. Hau, A thin-Film Oxygen Uptake Test for the Evaluation ofAutomotive Crankcase Lubricants, Lubrication Engineering, Vol. 40 (2),75-83 (1984). The test oil is a mineral oil-based motor oil thatcontains half the usual amount of zinc dithiophos-phate (0.75%; zinccontent 0.06%, based on the motor oil). This change was made in order tobe able to show a potential effect of the stabiliser to be tested.

Two commercially available 15 W40 motor oils with an adjusted content ofzinc dithiophosphate (ZDTP) are used as base oil:

oil A: 0.063% of phosphorus in the form of primary and secondary ZDTP(in the ratio 1:1)

oil B: 0.067% of phosphorus in the form of primary and secondary ZDTP(in the ratio 2:1).

The additive prepared in Example 1 is tested in the described motor oilin the presence of 2% of water, of a liquid, oxidised, nitrated fractionof a motor fuel as catalyst (4% concentration), of a liquid naphthenateas further catalyst (4% concentration; water and the two liquidcatalysts were supplied under the No. Standard Reference Material 1817by the National Bureau of Standards (NBS) with certificate of analysis).The test is complete when a distinct dip appears in the pressure/timediagram. The results reported in the following table indicate the time(in minutes) to the dip in the pressure/time diagram.

Lengthy times mean good stabiliser effectiveness. Concentration of thestabiliser: 0.5% by weight, based on the oil.

    ______________________________________                                                        Induction period [time                                                        (in minutes) to the dis-                                      Formulation     tinct drop in pressure]                                       ______________________________________                                        oil A            95                                                           oil A + 0.5% additive                                                                         170                                                           oil B           105                                                           oil B + 0.5% additive                                                                         170                                                           ______________________________________                                    

What is claimed is:
 1. A lubricant composition stabilized to reducefriction, wear, corrosion and oxidation, which comprises(a) one or moremineral oils or synthetic oils, and (b) 0.05 to 5% by weight, based onthe oil, of at least one compound of formula II ##STR24## wherein R¹ ishydrogen, C₁ -C₁₂ alkyl, C₂ -C₄ alkoxy, C₂ -C₂₄ alkoxycarbonyl or nitro,R² is hydrogen, C₁ -C₁₂ alkyl, 2-furyl, phenyl or phenyl which issubstituted by C₁ -C₄ alkyl, C₁ -C₄ alkoxy, C₂ -C₂₄ alkoxycarbonyl ornitro, and R³ is hydrogen, C₁ -C₂₀ alkyl, said alkyl interrupted by oneor more members selected from O, S and N atoms or said alkyl containingoxo or thiono groups; or is C₃ -C₂₄ alkenyl, C₃ -C₁₂ alkoxyalkyl, C₅ -C₈cycloalkyl, phenyl or phenyl which is substituted by C₁ -C₁₂ alkyl, C₁-C₄ alkoxy, C₂ -C₂₄ alkoxycarbonyl or nitro; or is naphthyl, C₇ -C₉phenylalkyl, 2-furylmethyl or 2-(tetrahydrofuryl)methyl.
 2. A lubricantcomposition according to claim 1, comprising 0.1 to 3% by weight of atleast one compound of formula II.
 3. A lubricant composition accordingto claim 1, which contains a compound of formula II, wherein the sum ofthe carbon atoms contained in the radicals R¹, R², and R³ is more than10.
 4. A lubricant composition according to claim 1, which contains acompound of formula II, wherein R² is hydrogen.
 5. A lubricantcomposition according to claim 4, which contains a compound of formulaII, wherein R¹ is hydrogen.
 6. A lubricant composition according toclaim 5, which contains a compound of formula II, wherein R³ ishydrogen, C₁ -C₂₄ alkyl, C₃ -C₂₄ alkenyl, cyclohexyl, phenyl, phenylwhich is substituted by C₁ -C₁₂ alkyl or C₂ -C₂₄ alkoxycarbonyl, or isC₇ -C₁₀ phenylalkyl, 2-methoxyethyl or 3-methoxypropyl.
 7. A lubricantcomposition according to claim 1, which contains a compound of formulaII of formula ##STR25##
 8. A compound of formula II ##STR26## wherein R¹is hydrogen, C₁ -C₁₂ alkyl, C₂ -C₄ alkoxy, C₂ -C₂₄ alkoxycarbonyl ornitro,R² is hydrogen, C₁ -C₁₂ alkyl, 2-furyl, phenyl or phenyl which issubstituted by C₁ -C₄ alkyl, C₁ -C₄ alkoxy, C₂ -C₂₄ alkoxycarbonyl ornitro, and R³ is hydrogen, C₁ -C₂₀ alkyl, said alkyl interrupted by oneor more members selected from O, S and N atoms or containing oxo orthiono groups; or is C₃ -C₂₄ alkenyl, C₃ -C₁₂ alkoxyalkyl, C₅ -C₈cycloalkyl, phenyl or phenyl which is substituted by C₁ -C₁₂ alkyl, C₁-C₄ alkoxy, C₂ -C₂₄ alkoxycarbonyl or nitro; or is naphthyl, C₇ -C₉phenylalkyl, 2-furylmethyl or 2-(tetrahydrofuryl)methyl;with the provisothat R² and R³ together contain more than 10 carbon atoms.
 9. A compoundof formula II according to claim 8, wherein R² is hydrogen.
 10. Acompound of formula II according to claim 8, wherein R¹ and R² arehydrogen and R³ contains more than 10 carbon atoms.
 11. The compoundaccording to claim 8 which has the formula ##STR27##